(1. 西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055；2. 武漢鋼鐵股份有限公司，武漢 430080)
摘 要: 在Gleeble−1500熱模擬機(jī)上對(duì)120°模具室溫Bc方式ECAP變形8道次制備的平均晶粒尺寸約為200 nm的工業(yè)純鈦進(jìn)行等溫變速壓縮實(shí)驗(yàn)，研究超細(xì)晶工業(yè)純鈦在變形溫度為298~673 K和應(yīng)變速率為1×10−4~1×100 s−1條件下的流變應(yīng)力行為。結(jié)果表明：變形溫度和應(yīng)變速率均對(duì)流變應(yīng)力具有顯著影響，峰值應(yīng)力隨變形溫度的升高和應(yīng)變速率的降低而降低；流變應(yīng)力在變形初期隨應(yīng)變的增加而增大，出現(xiàn)峰值后逐漸趨于平穩(wěn)，呈現(xiàn)穩(wěn)態(tài)流變特征。采用雙曲正弦模型確定了超細(xì)晶工業(yè)純鈦的變形激活能Q=104.46 kJ/mol和應(yīng)力指數(shù)n=23，建立了相應(yīng)的變形本構(gòu)關(guān)系。
關(guān)鍵字: 超細(xì)晶工業(yè)純鈦；熱壓縮變形；流變應(yīng)力；本構(gòu)關(guān)系；變形激活能
（1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;
2. Wuhan Iron and Steel Company Limited, Wuhan 430080, China）
Abstract:The hot compression deformation behavior of ultrafine-grained (UFG) commercially pure (CP) Ti with the average grain size of about 200 nm was studied by isothermal simulation tests at the deformation temperature of 298− 673 K and the strain rate of 1×10−4−1×100 s−1 on the Gleeble−1500 thermal-mechanical simulator. UFG CP-Ti was produced by ECAP up to 8 passes with a die of 120° using route Bc at room temperature. The results show that the deformation temperature and strain rate greatly affect the flow stress. The peak stress decreases with increasing deformation temperature and decreasing strain rate. The flow stress increases with increasing strain and tends to be constant after a peak value which is the characteristic of the steady flow state. The deformation activation energy and stress exponent were obtained using the hyperbolic-sine mathematics model to be Q=104.46 kJ/mol and n=23, and the hot deformation constitutive relationship was established.
Key words: ultrafine-grained commercially pure (CP)-Ti; hot compression deformation; flow stress; constitutive relationship; deformation activation energy
